Internal combustion engine



Jan. 17, 1961 INTERNAL COMBUSTION ENGINE Filed Jan. 12, 1959 I 2 Sheets-Sheet 1 s. MEURER 2,968,298

r V 5 y F! i 7 Z 4Z I 43 5 S. MEURER INTERNAL COMBUSTION ENGINE Jan. 17, 1961 2 SheetsSheet 2 Filed Jan. 12, 1959 1' NQWW A INVENTOR. g fijgg/fi) MEURER INTERNAL COMBUSTION ENGINE Siegfried Meurer, Heisterstrasse 37, Numberg, Germany 'Filed Jan. 12, 1959, Ser. No. 786,272

11 Claims. (Cl. 123-139) This invention relates to internal combustion engines of the fuel-injection type, and more particularly to engines in which the injected material comprises a mixture of two different liquids. The injection of a mixture of liquids into the cylinders of an internal combustion engine is most commonly employed in diesel engines where, during starting and warm-up, the delay in ignition of ordinary diesel-engine fuels results in poor performance. It has therefore been proposed to add an ignition-accelerator to a diesel fuel, at least during starting and warming up of the engine, thereby effecting a substantial improvement in the starting and warm-up characteristics.

I have discovered that ordinary lubricating oil of the type used in the lubricating system of internal combus tion engines has ignition-accelerating properties. This invention therefore contemplates the provision of means for adding to the ordinary engine fuel a small, controlled proportion of lubricating oil. The means employed to accomplish that end may take different forms, but in the most desirable arrangements the lubricating oil for addition to the fuel is drawn from the lubricating system of the engine. In the preferred arrangement, means are provided for effecting a temporary connection between the lubricating system of the fuel-injection pump and the inlet of such pump, so that during each cycle of operation a small quantity of lubricating oil will be added to the conventional fuel. a

Pursuing further this general idea of tapping small amounts of lubricating oil from-the lubricating system of an injection type internal combustion engine and delivering it into the fuel injection system it is proposed to inject lubricating oil not only during starting as ignition accelerator but also during regular operation of the engine, the amount so added being varied to suit any particuler type of fuel out of the range burnt in multi-fuel engines (gas oil, gasolines, alcohol).

- It is known that the contamination of the lubricating oil by soot oracid products of combustion differs for the various types of fuel. Whereas in the case of diesel fuels the contamination by solid impurities is relatively high, there is little contamination by acids. If the same engine is operated on gasolines the deterioration of the lubricating oil will be greater and mainly by acid dilution. If then the inherent lubricating oil consumption of an engine is small it will take quite some time before it becomes necessary to top up the oil level and thus to add a sufiicient amount of fresh oil and restore the cleansing action of the oil (fresh additives). Therefore the engine is liable to suffer from the effects of sludge formation and the resulting clogging of the piston rings, excessive wear of the bearings, etc., although the lubricating oil level is Within the prescribed limits. It is not possible to rely on the operators judgement in deciding on how the interval between oil changes should be varied to allow for the different effects of various fuels on the lubricating oil. For this reason it is desirable that the oil consumption of the engine should be in proportion to the deterioration of the fuel used in a multi-fuel engine at a particular time.

2,968,298 "Patented Jan. 17, 1961 the contrary, the oil injected is not lost but burnt as a' fuel and converted into power in the engine.

Mechanically this is achieved by retaining the said connection between the lubricating system of the fuel injection pump and the inlet of such pump throughout the operation of the engine. This connection is effected by a groove-and-port arrangement involving the pump plunger, pump barrel and the sleeve of the injection pump.

The amount of lubricating oil tapped from the lubricating oil system of the injection pump need be but very small, the best proportion being of the order of 1% of the amount of fuel injected. This results in a low-rate lubricating oil consumption which provides the operator with an indication of the oil deterioration and enables him to maintain the necessary oil quality over a scheduled mileage between oil changes so that the intervals between oil changes remain the same no matter whether highly volatile fuels (gasolines) or gas oil was used. Since when using highly volatile fuels of low viscosity the injection pump usually requires additional means of lubrication, the abovementioned lubricating arrangement for the injection pump plunger may be considered stand- Fig. 2 is a fragmental section on the line 2-2 of Fig. 1

showing details of an injection pump;

Fig. 3 is a fragmental side elevation of a modified form of pump-plunger;

Fig. 4 is a transverse section on the line 44 of Fig. 3;

Fig. 5 is a fragmental view of a fuel pump, in partial section, showing a modified arrangement for effecting temporary connection of the lubricating system to the inlet side of the pump;

Fig. 6 is a fragmental section on the line 6-6 of Fig. 5; and

Fig. 7 is a view similar to Fig. 1 showing still another embodiment of the invention.

In Fig. l, I have indicated a six-cylinder diesel engine 10 having the usual fuel pump 11 which forces the fuel in timed sequence through conduits 11' to the injection nozzles 12 of the several cylinders. The fuel pump 11 is supplied with fuel from any appropriate container 13 by a feed pump 14 discharging through a conduit 15. The engine is provided with a lubricating system including a pump 16 which withdraws lubricating oil from an appropriate source, such as the crank case of the engine, and discharges it through a conduit 17 provided with quiring lubrication.

running parts thereof. 7

In the construction shown in Fig. 2, the fuel pump 11 comprises a body 20 in which a series of sleeves 21,

corresponding in number to the injection nozzles 12, are mounted in parallel relation. The interior of each sleeve 21 constitutes a cylinder which receives a reciprocable plunger 22 and which communicates at its upper end with one of the conduits 11 past the usual spring-loaded check-valve 23. Extending longitudinally of the body 20 is a passage or chamber 24 connected in any convenient manner to the fuel supply line 15. Each of the sleeves 21 extends vertically through the passage 24 and is provided within the limits thereof with an inlet port 25 adapted to be alternately covered and uncovered in the reciprocation of the plunger 22.

A lubricating oil passage 27 extends longitudinally of the pump body 20 and is connected at one end to the lubricant-supply line 18. Individual oil passages 28 conduct oil from the passage 27 to the interiors of the several sleeves 21, opening thereinto below the chamber 24. The oil passages 23 normally serve to provide a lubricatingoil film 30 between the opposed surfaces of each plunger 22 and its associated sleeve 21. As the consumption of lubricating oil at this point is low, it is not customary to provide for any oil return.

In adapting a fuel pump of the type shown in Fig. 2 for incorporation of my invention, I provide means for effecting a temporary interconnection of the lubricant passage 27 and the fuel chamber 24. In the form shown, this interconnection includes a port 32 provided in the wall of a sleeve 21 to effect a connection between the chamber 24 and the interior of the sleeve. In addition, the plunger 22 is provided with a longitudinally extended groove 33 which, for a limited portion of the stroke of the plunger 22, affords an interconnection between the lubricant passage 28 and the port 32. During the interval in which the groove 33 provides a connection between the lubricant passage 28 and the chamber 24 lubricant will be discharged from the lubricating system of the engine into the chamber 24 where, mixed with the fuel therein, it will be supplied through the port 25 to the interior of the sleeve 21 and injected into the cylinder on the working stroke of the plunger.

In order that interconnection of the passage 28 and port 32 through the groove 33 may be independent of the angular disposition of the plunger 22 about its axis, the sleeve 21 is shown as provided interiorly and in the plane of the port 32 with an annular groove 35 and the plunger 22 is shown as provided with an annular groove 36 communicating with the lower end of the longitudinal groove 33. Many fuel injection pumps are so constructed that the amount of fuel injected at each stroke of each plunger can be varied by adjusting the plunger about its axis. The annular grooves 35 and 36 shown in Fig. 2 permit such adjustment to be made without interfering with the delivery of lubricating oil to the chamber 24 through the port 32, groove 33, and passage 28.

The amount of lubricating oil delivered to the chamber 24 at each stroke of the plunger will be a function of the length of the time interval during which the passage 28 and port 32 are interconnected. The duration of that time interval will depend on two factors-viz., on the effective length of the groove 33 relative to the spacing between the port 32 and passage 28 and on the position of the plunger during the interval in which such port and passage are interconnected. If, as indicated in Fig. 2, the plunger is at or near one end of its stroke while the groove 33 is interconnecting the passage 28 and port 32, the plunger will be moving slowly and a relatively large amount of lubricating oil will be delivered to the chamber 24. On the other hand, if the plunger is nearer the mid-point of its stroke when the port 32 and passage 23 are interconnected, the plunger will be moving rapidly and a small amount of lubricating oil will be delivered to the chamber 24. Other factors affecting the rate at which lubricating oil is supplied to the fuel are the crosssectional areas of the passages 28, 33, and 32, the number of plungers provided with the grooves 33, and the effective lubricating-oil pressure, which can be controlled by a valve 37 in the conduit-branch 18.

Instead of employing in the plunger 22 a groove 36 which is of uniform cross-sectional area through the entire circumference of the plunger, I may provide the plunger with a groove of varying cross-sectional area, as indicated at 40 in Figs. 3 and 4. As there shown, the groove has a maximum cross-sectional area at one end and decreases in both width and depth toward the other end. By adjusting about its axis a plunger provided with a groove 40, the amount of lubricating oil delivered to the fuel system at each stroke of the plunger can be varied as desired. In fuel pumps wherein the plungers are rotatable about their axes to vary fuel delivery, the grooves 40 can be positioned and shaped to maintain any desired ratio between the rates of fuel and lubricating-oil delivery to the nozzles 12.

Another method of maintaining a desired ratio between the rates of fuel and lubricating-oil supply involves the use, in the fuel-line 15, of a restriction which will create a pressure-drop that varies with the rate of fuel delivery. Such a restriction may be an adjustable valve such as indicated at 51 in Fig. 1, but it is not necessarily adjustable. At the higher engine speeds, such a constriction reduces the pressure in the chamber 24 below what it would otherwise be, thus resulting in increasing the amount of lubricating oil delivered to such chamber through the passage 33 at each stroke of the pump plunger 22.

Instead of employing reciprocation of fuel-injection plungers to effect a temporary interconnection of the lubricating and fuel-supply systems, I may employ rotation of one of the engine shafts. Such an arrangement is indicated in Fig. 5. Here, the shaft 42 which carries the cams 43 that operate the several plungers 22 is shown as supported in bearings 44. In the plane of one of such bearings, the shaft 42 is provided with a transverse passage 45 adapted to register at each halfrevolution of the shaft 42 with diametrically opposite passages 46 and 47 in the bearing. One of such passages, shown as the passage 46 is connected to the fuelsupply line 15 by a conduit 46 while the other passage is connected to a branch 48 of the lubricant-conduit 17. With such an arrangement, whenever the passage .45 in the shaft registers with the passages 46 and 47 a small quantity of lubricating oil will be added to the fuel supplied to the pump 11. The quantity of lubricating oil so added to the fuel can be controlled by means of an adjustable valve 49 in the branch conduit 48.

In the operation of the devices so far described, the valve 37 or 49 in the line from the lubricating system is opened prior to starting the engine. The lubricating oil added to the fuel serves as an ignition accelerator during engine starting and warm-up. When the engine attains normal operating temperature and an ignition accelerator is no longer needed, the valve 37 (or 49) is closed to terminate the supply of lubricant. As indicated in the case of the valve 37 in Fig. 1, the valve controlling the supply of lubricating oil to the fuel system may be automatically operated under the control of a temperature-responsive element 53 responsive to engine temperature and operative through any appropriate form of motor 54 'to close the valve when a' predetermined engine temperature is attained.

The arrangement of Fig. 7 is similar to that of Fig. 1 except that the supply of lubricant to the fuel system is effected manually. In such an arrangement I employ a manually operated pump 55 having a suction line 56 communicating with the lubricant sump of the engine and a. delivery line 57 communicating with the fuel line 15. Through operation of the manual pump 55, lubricant can be Withdrawn from the lubricant system and delivered to the fuel system during the starting and Warm-up of the engine.

This application is a continuation-in-part of each of my prior copending applications Serial No. 567,397, filed February 23, 1956, and Serial No. 684,244, filed September 16, 1957, both of which are now abandoned in favor of this application.

I claim as my invention:

1. In a compression-ignition internal combustion engine having a combustion chamber, means for injecting liquid fuel into said combustion chamber, and a lubricating system through which lubricating oil is circulated;

means for withdrawing small quantities of the lubricating oil from said lubricating system and supplying them to said fuel-injection means.

2. The invention of claim 1 with the addition that said last named means is driven by the engine and receives lubricating oil through a conduit communicating with said lubricating system.

3. The invention of claim 2 with the addition of a valve in said conduit, and means responsive to the temperature of the engine for controlling said 'valve to terminate the supply of lubricating oil to the fuel-injection means.

4. The invention of claim 2 with the addition of a valve in said conduit, and means responsive to the temperature of the engine for controlling said valve.

5. The invention ofclaim 2 with the addition of a valve in said conduit.

6. The invention of claim 1 with the addition of means responsive to the temperature of the engine for controlling the supply of lubricating oil to said fuelinjection means.

7. The invention of claim 1 with the addition that said last named means is engine driven and includes provisions for establishing a controlled short-time connection between the lubricating system and said fuel-injection means.

8. An apparatus for controlling the lubrication oil consumption of a fuel injection internal combustion engine comprising a fuel injection pump having a cylinder, a fuel plunger reciprocable therein, and a fuel intake suction chamber in controlled communication with said cylinder, an engine connected lubricating system having a lubricating oil line joined to said pump, and pump actuated means for establishing a controlled short time communication between said oil line and said suction chamber during operation of said pump. 1 9. In combination with a high speed diesel engine having a fuel supply system, a fuel-injection nozzle, and a lubricating system, means for feeding lubricant in controlled quantities from said lubricating system to said fuel supply system at a point therein anterior to said nozzle for admixture and simultaneous injection with the fuel.

10. The combination of claim 9 with the addition that said lubricating system is a circulating system having a pressure side, said feeding means comprising a connection between the pressure side of the lubricating system and the fuel-supply system.

11. The combination of claim 9 with the addition that said feeding means is a manually operated pump having an inlet connected to said lubricating system and an outlet connected to said fuel supply system.

References Cited in the file of this patent UNITED STATES PATENTS 1,904,936 Stokes Apr. 18, 1933.

2,440,196 Fenney Apr. 20, 1948 2,811,145 Young Oct. 29, 1957 FOREIGN PATENTS 720,222 Great Britain Dec. 15, 1954 

